Muscular system
Muscular system
Skeletal muscles and their attachments and actions.
123 structures
Study guides for this system: How to memorize muscle origins and insertions and The rotator cuff muscles, explained.
Upper limb
49Abductor digiti minimi (hand)
Moves the little finger away from the others
MuscleAbductor pollicis brevis
Lifts the thumb out of the plane of the palm
MuscleAbductor pollicis longus
Moves the thumb at its base
MuscleAdductor pollicis
Brings the thumb inward for a firm pinch
MuscleAnconeus
Small helper at the back of the elbow
MuscleBiceps brachii
Turns the forearm palm-up and bends the elbow
MuscleBrachialis
Elbow flexion regardless of palm position
MuscleBrachioradialis
Radial-supplied flexor on the outer forearm
MuscleCoracobrachialis
Links the coracoid to the medial arm
MuscleDeltoid
Shoulder cap with three directions of pull
MuscleDorsal interossei (hand)
Spread the fingers around the middle-finger axis
MuscleExtensor carpi radialis brevis
Short radial wrist extensor
MuscleExtensor carpi radialis longus
Long radial wrist extensor
MuscleExtensor carpi ulnaris
Wrist extension toward the ulna
MuscleExtensor digiti minimi
Additional little-finger extensor
MuscleExtensor digitorum
Extensor shared by four fingers
MuscleExtensor indicis
Separate extension for the index finger
MuscleExtensor pollicis brevis
Straightens the thumb at the MCP joint
MuscleExtensor pollicis longus
Extensor of the thumb's terminal joint
MuscleFlexor carpi radialis
Bends the wrist toward the thumb side
MuscleFlexor carpi ulnaris
Bends the wrist toward the little finger
MuscleFlexor digiti minimi brevis (hand)
Bends the little finger at its knuckle
MuscleFlexor digitorum profundus
Flexor that reaches the fingertips
MuscleFlexor digitorum superficialis
Flexor that stops at the middle phalanges
MuscleFlexor pollicis brevis
Short thumb flexor with variable nerve supply
MuscleFlexor pollicis longus
Deep flexor of the thumb tip
MuscleInfraspinatus
Posterior cuff muscle for outward rotation
MuscleLatissimus dorsi
Broad back muscle that pulls on the upper arm
MuscleLevator scapulae
Connects the upper neck to the shoulder blade
MuscleLumbricals (hand)
Coordinate a bent knuckle with straighter finger joints
MuscleOpponens digiti minimi
Turns the fifth metacarpal to cup the palm
MuscleOpponens pollicis
Turns the thumb pad toward the fingertips
MusclePalmar interossei
Draw the fingers back toward the middle-finger axis
MusclePalmaris longus
Variable tendon to the palmar fascia
MusclePectoralis major
Large chest muscle for bringing the arm inward
MusclePectoralis minor
Pulls the scapula toward the front of the chest
MusclePronator quadratus
Short pronator near the wrist
MusclePronator teres
Proximal forearm pronator
MuscleRhomboid major
Draws the shoulder blade toward the spine
MuscleRhomboid minor
Small retractor at the root of the scapular spine
MuscleSerratus anterior
Keeps the shoulder blade against the rib cage
MuscleSubclavius
Short stabilizer beneath the clavicle
MuscleSubscapularis
Anterior cuff muscle for inward rotation
MuscleSupinator
Rotates the radius into supination
MuscleSupraspinatus
Helps lift the arm and center the shoulder joint
MuscleTeres major
Pulls the arm inward and backward
MuscleTeres minor
Small external rotator within the cuff
MuscleTrapezius
Positions the scapula for shoulder movement
MuscleTriceps brachii
Main muscle for straightening the elbow
MuscleLower limb
38Adductor brevis
Short adductor between two nerve divisions
MuscleAdductor longus
Superficial adductor at the femoral triangle
MuscleAdductor magnus
Broad hip adductor with a hamstring-like portion
MuscleBiceps femoris
Two-headed muscle along the outer posterior thigh
MuscleExtensor digitorum longus
Anterior leg muscle sending tendons to toes two through five
MuscleExtensor hallucis longus
Long extensor connecting the fibula to the great toe
MuscleFibularis brevis
Shorter lateral leg muscle attaching to the fifth metatarsal
MuscleFibularis longus
Lateral leg muscle whose tendon crosses beneath the foot
MuscleFibularis tertius
Variable anterior-compartment muscle assisting foot eversion
MuscleFlexor digitorum longus
Long flexor reaching the tips of the four smaller toes
MuscleFlexor hallucis longus
Deep leg flexor carrying force to the great toe
MuscleGastrocnemius
Two-headed calf muscle linking the knee and heel
MuscleGluteus maximus
Large superficial muscle that drives hip extension
MuscleGluteus medius
Broad lateral hip muscle supporting one-leg stance
MuscleGluteus minimus
Deep gluteal muscle helping steady the hip joint
MuscleGracilis
Slender medial-thigh muscle reaching the tibia
MuscleIliacus
Broad iliac-fossa partner of psoas major
MuscleInferior gemellus
Lower muscle bordering the obturator internus tendon
MuscleObturator externus
Deep hip rotator arising outside the obturator membrane
MuscleObturator internus
Pelvic-wall muscle with a tendon turning toward the hip
MusclePectineus
Short muscle bridging pubis and upper femur
MusclePiriformis
Hip rotator marking routes through the greater sciatic foramen
MusclePlantaris
Small calf muscle with a long, variable tendon
MusclePopliteus
Deep knee muscle controlling rotation at the start of flexion
MusclePsoas major
Spine-to-femur muscle contributing to hip flexion
MuscleQuadratus femoris
Short posterior hip muscle linking ischium and femur
MuscleRectus femoris
Quadriceps muscle acting at both hip and knee
MuscleSartorius
Long diagonal strap across the anterior thigh
MuscleSemimembranosus
Deep medial hamstring with an expanded proximal tendon
MuscleSemitendinosus
Medial hamstring ending in a long tibial tendon
MuscleSoleus
Deep calf muscle supporting standing and ankle push-off
MuscleSuperior gemellus
Upper partner of the obturator internus tendon
MuscleTensor fasciae latae
Lateral hip muscle that tensions the iliotibial tract
MuscleTibialis anterior
Anterior leg muscle lifting and turning the foot inward
MuscleTibialis posterior
Deep leg muscle helping support the medial foot arch
MuscleVastus intermedius
Deep quadriceps component against the femur
MuscleVastus lateralis
Large lateral contributor to knee extension
MuscleVastus medialis
Medial quadriceps muscle supporting the extensor system
MuscleThorax
3Abdomen
5External oblique
Superficial sheet linking the ribs to the abdominal wall
MuscleInternal oblique
Abdominal layer with regionally changing fiber direction
MuscleQuadratus lumborum
A muscular connection between pelvis, lumbar spine and rib 12
MuscleRectus abdominis
Paired vertical muscles inside the rectus sheath
MuscleTransversus abdominis
Deep abdominal muscle supporting pressure and stability
MusclePelvis
1Back
3Head & neck
24Anterior scalene
First-rib elevator beside the brachial plexus
MuscleBuccinator
Keeps the cheek close to the teeth
MuscleDigastric
Two bellies linking the jaw and hyoid
MuscleGenioglossus
Fan-shaped muscle that advances the tongue
MuscleHyoglossus
Hyoid-to-tongue muscle beside key oral structures
MuscleIntrinsic muscles of the tongue
Interwoven fibers for precise tongue shape
MuscleLateral pterygoid
Advances the mandibular condyle
MuscleLevator veli palatini
Muscular sling that lifts the soft palate
MuscleMasseter
Powerful jaw-closing muscle
MuscleMedial pterygoid
Inner partner of the jaw-closing sling
MuscleMylohyoid
Paired support beneath the tongue
MuscleOccipitofrontalis
Moves the scalp and lifts the brows
MuscleOmohyoid
Two-bellied connection from scapula to hyoid
MuscleOrbicularis oculi
Protective muscle for eyelid closure
MuscleOrbicularis oris
Shapes and seals the lips
MusclePalatoglossus
Links the soft palate to the tongue
MusclePharyngeal constrictor muscles
Overlapping muscles that propel a swallowed bolus
MusclePlatysma
Thin sheet moving the superficial neck tissues
MuscleSternocleidomastoid
Surface landmark and head-turning muscle
MuscleSternohyoid
Superficial strap that lowers the hyoid
MuscleStyloglossus
Draws the tongue backward and upward
MuscleTemporalis
Fan-shaped jaw elevator and retractor
MuscleTensor veli palatini
Tenses the palate and helps open the auditory tube
MuscleZygomaticus major
Raises the mouth corner during a smile
Muscle